digraph {
  graph [splines=polyline,rankdir=TB,ranksep=1.0,nodesep=1.0,fontsize=5]
  node [shape=box,fontsize=5]
  edge []

  subgraph cluster_enterprise {
    margin=25
    2 [width=1.500000,height=1.000000,fixedsize=true,id=2,label="2: Software System"]
  }

  1 [width=1.333333,height=1.333333,fixedsize=true,id=1,label="1: User"]

  1 -> 2 [id=3]
}